Fixing belt having a protective layer between a metal heating layer and a releasing layer, manufacturing method thereof, and electromagnetic induction heat-fixing device using the fixing belt

Abstract

The present invention provides a fixing belt including a substrate having provided thereon at least a metal heating layer and a releasing layer, wherein at least a protective layer is provided between the metal heating layer and the releasing layer, a manufacturing method thereof, and an electromagnetic induction heat-fixing device using the same.

1. A fixing belt comprising a substrate having provided thereon at least a metal heating layer and a releasing layer, wherein at least a protective layer is provided between the metal heating layer and the releasing layer, wherein a thickness t a  of the substrate, an elastic modulus E a  of the substrate, a thickness t b  of the protective layer, and an elastic modulus E b  of the protective layer satisfy the following equation (1)
   0.05≦{( t   b   ×E   b )/( t   a   ×E   a )}≦1  (1). 
 
   
   
     2. A fixing belt of  claim 1 , wherein the substrate is made from a heat-resistant resin. 
   
   
     3. A fixing belt of  claim 1 , wherein the substrate is made from a polyimide. 
   
   
     4. A fixing belt of  claim 1 , wherein the protective layer is a thermoplastic resin layer. 
   
   
     5. A fixing belt of  claim 1 , wherein an elastic layer is provided between the protective layer and the releasing layer. 
   
   
     6. A fixing belt of  claim 1 , wherein a thermoplastic resin layer is provided between the substrate and the metal heating layer. 
   
   
     7. A fixing belt of  claim 1 , wherein a thermoplastic polyimide layer is provided between the substrate and the metal heating layer. 
   
   
     8. A fixing belt of  claim 1 , further comprising a coil for generating an alternating magnetic field in the belt. 
   
   
     9. A fixing belt comprising a substrate having provided thereon at least a metal heating layer and a releasing layer, wherein at least a protective layer is provided between the metal heating layer and the releasing layer, wherein the elastic modulus E a  of the substrate and the elastic modulus E b  of the protective layer satisfy the following equation (2)
   E b ≧E a   (2). 
 
   
   
     10. A fixing belt comprising a substrate having provided thereon at least a metal heating layer and a releasing layer, wherein at least a protective layer is provided between the metal heating layer and the releasing layer, wherein the thickness t b  of the protective layer and the thickness t c  of the metal heating layer satisfy the following equation (3)
   10 ≧t   b   /t   c ≧1  (3). 
 
   
   
     11. A fixing belt comprising a substrate having provided thereon at least a metal heating layer and a releasing layer, wherein at least a protective layer is provided between the metal heating layer and the releasing layer, wherein the protective layer is a thermoplastic polyimide resin layer. 
   
   
     12. A fixing belt comprising a substrate having provided thereon at least a metal heating layer and a releasing layer, wherein at least a protective layer is provided between the metal heating layer and the releasing layer, wherein the protective layer is a thermoplastic polyimide resin layer formed by applying a solution of a thermoplastic polyimide resin in a state where it has been completely imidized. 
   
   
     13. A fixing belt comprising a substrate having provided thereon at least a metal heating layer and a releasing layer, wherein at least a protective layer is provided between the metal heating layer and the releasing layer, wherein a thermoplastic resin layer formed by applying a solution of a thermoplastic polyimide resin in a state where it has been completely imidized is provided between the substrate and the metal heating layer; and
 wherein a thickness t a  of the substrate, an elastic modulus E a  of the substrate, a thickness t b  of the protective layer, and an elastic modulus E b  of the protective layer satisfy the following equation (1)
   0.05≦{( t   b   ×E   b )/( t   a   ×E   a )}≦1  (1). 
 
 
   
   
     14. An electromagnetic induction heat-fixing device comprising:
 a fixing belt comprising a substrate having provided thereon at least a metal heating layer and a releasing layer; 
 a press roll that abuts against the fixing belt to form a nip and rotates; 
 a press contact member for increasing a nip pressure; and 
 an excitation coil, 
 wherein an eddy current is generated in the metal heating layer, which is included in the fixing belt, by a magnetic field generated by running an electrical current through the excitation coil to heat a surface of the metal heating layer, and a recording material having an unfixed toner image formed thereon is passed through the nip in such a way that the unfixed toner image abuts against the fixing belt to fuse the unfixed toner image and fix the image to the recording material by pressure, and wherein the fixing belt has at least a protective layer provided between the metal heating layer and the releasing layer, and wherein the elastic modulus E b  of the protective layer is 2 GPa or more; and 
 wherein a thickness t a  of the substrate, an elastic modulus E a  of the substrate, a thickness t b  of the protective layer, and an elastic modulus E b  of the protective layer satisfy the following equation (1)
   0.05≦{( t   b   ×E   b )/( t   a   ×E   a )}≦1  (1). 
 
 
   
   
     15. A method of manufacturing a fixing belt comprising a substrate having provided thereon at least a metal heating layer and a releasing layer, the method comprising:
 forming a protective layer between the metal heating layer and the releasing layer; and 
 heat-treating the protective layer at a temperature of 200° C. or more, 
 wherein a thickness t a  of the substrate, an elastic modulus E a  of the substrate, a thickness t b  of the protective layer, and an elastic modulus E b  of the protective layer satisfy the following equation (1).
   0.05≦{( t   b   ×E   b )/( t   a   ×E   a )}≦1  (1). 
 
 
   
   
     16. A method of manufacturing a fixing belt of  claim 15 , wherein the heat treatment step involves running a high-frequency current for generating an alternating magnetic field in a coil arranged near the fixing belt so as to generate an eddy current in the fixing belt's metal heating layer, thereby heating the protective layer to 200° C. or more by electromagnetic induction heating. 
   
   
     17. A method of manufacturing a fixing belt of  claim 15 , wherein the fixing belt has a coil for generating an alternating magnetic field and the heat treatment step involves running a high-frequency current for generating an alternating magnetic field in the coil so as to generate an eddy current in the fixing belt's metal heating layer, thereby heating the protective layer to 200° C. or more by electromagnetic induction heating. 
   
   
     18. A fixing belt comprising a substrate having provided thereon at least a metal heating layer and a releasing layer, wherein at least a thermoplastic resin layer is provided between the substrate and the metal heating layer, and wherein the thermoplastic resin layer is a thermoplastic polyimide resin layer formed by applying a solution of a thermoplastic polyimide resin in a state where it has been completely imidized; and
 wherein a thickness t a  of the substrate, an elastic modulus E a  of the substrate, a thickness t b  of the protective layer, and an elastic modulus E b  of the protective layer satisfy the following equation (1)
   0.05≦{( t   b   ×E   b )/( t   a   ×E   a )}≦1  (1). 
 
 
   
   
     19. A fixing belt of  claim 18 , wherein an elastic layer is provided between the protective layer and the releasing layer. 
   
   
     20. A fixing belt of  claim 18 , wherein the thermoplastic resin layer is a thermoplastic polyimide layer. 
   
   
     21. A fixing belt of  claim 18 , wherein the fixing belt has a coil for generating an alternating magnetic field. 
   
   
     22. A method of manufacturing a fixing belt comprising a substrate having provided thereon at least a metal heating layer and a releasing layer, the method comprising:
 forming a thermoplastic resin layer between the substrate and the metal heating layer; and 
 heat-treating the protective layer at a temperature of 200° C. or more, 
 wherein a thickness t a  of the substrate, an elastic modulus E a  of the substrate, a thickness t b  of the thermoplastic resin layer, and an elastic modulus E b  of the thermoplastic resin layer satisfy the following equation (1)
   0.05≦{( t   b   ×E   b )/( t   a   ×E   a )}≦1  (1). 
 
 
   
   
     23. A method of manufacturing a fixing belt of  claim 22 , wherein the heat treatment step involves running a high-frequency current for generating an alternating magnetic field in a coil arranged near the fixing belt so as to generate an eddy current in the fixing belt's metal heating layer, thereby heating the protective layer to 200° C. or more by electromagnetic induction heating. 
   
   
     24. A method of manufacturing a fixing belt of  claim 22 , wherein the fixing belt has a coil for generating an alternating magnetic field and the heat treatment step involves running a high-frequency current for generating an alternating magnetic field in the coil so as to generate an eddy current in the fixing belt's metal heating layer, thereby heating the protective layer to 200° C. or more by electromagnetic induction heating.